This Unreal Engine 5.4 video is about spawning waves based on the previous video’s Data Driven Wave Data.
We start by adding a Wave Data entry in the JSON file for the Green Enemy, which we create from Enemy Base, in the Editor. Next, we updated the Wave Manager Blueprint to include the new Green Enemy, and ensure Import Data is being called. We then add logic to Update Wave, to iterate through the Wave Data Array, Spawning a new Enemy when Delay Remaining is zero, and updating that Wave Data Struct as appropriate.
https://dev.epicgames.com/community/learning/tutorials/awGz/unreal-engine-09-the-wave-manager-making-waves-let-s-make-a-tower-defense-game